Weeding out fallacies from arguments is at the root of right judgment. Shutterstock

In the first part of this series, we looked at the way the Catholic intellectual tradition teaches that grace builds on nature through the thought process just as with everything else. As Jesus takes natural actions like bathing or eating and raises them, by grace, to the sacraments of baptism and the Eucharist, so he takes the rest of our lives and makes them the means of grace as well.

This means that if we are to worship God with our minds, as he commands us to do, we have to train these minds to be the best they can be. That is why Jesus says, “Stop judging by appearances, but judge justly” (Jn 7:24).

This immediately, however, causes a problem: namely, that thinking is complicated and filled with many pitfalls. Take, for instance, the problem of “judging justly.” How can Jesus say this when elsewhere he famously says, “Judge not, that you be not judged” (Mt 7:1). Is Jesus contradicting himself?

Defining contradiction

To answer that, we need to know what a “contradiction” is and what it isn’t. Many statements that seem like contradictions are not contradictions at all, as every reader of stories with twist endings knows.

When Shakespeare’s Macbeth is assured that no man born of woman can kill him, he thinks it a contradiction and, therefore, imagines himself invulnerable — until he discovers Macduff was delivered by Caesarean section and is dispatched by him.

Similarly, we can falsely assume that “judging” is a word that only has one sense, when in fact it has many. Judging can mean, for instance, “to exercise prudence and rightly assess reality,” or it can mean “to set yourself up in the place of God and decide who is and is not worthy of salvation.” The former is what Jesus commends, and the latter is what he condemns.

In short, the word “contradiction” asserts that a thing both “is” and “is not” at the same time and in the same respect. Jesus is not doing that, hence no contradiction.

On the other hand, real contradictions exist, forcing us to make real choices. For instance, either God exists or he does not exist. There’s no third alternative. People who say, “He’s real for you, but not for me” mean “He’s not real, but I’ll humor deluded people like you.” People who say, “He’s real for me, though not for you” mean either, “I accept the fact that a real God exists, but also accept that you have trouble perceiving his existence” (which is not a self-contradictory statement). Or they mean nonsense about a figment of their imagination who — as Santa Claus — “lives in our hearts.” Which is another way of saying, “God does not exist.”

One thing we can do while learning how to think is to practice applying the law of non-contradiction — that contradictory statements can’t be both true in the same sense at the same time — to the things we, and others, say. That will help us see how much of our conversation is “wooly-minded rubbish” that either imagines false contradictions or tries to paper over real ones.

Recognizing differences

It’s also handy to be able to distinguish among a “non sequitur,” a “valid argument” and a “sound argument.”

A non sequitur is an argument where the conclusion does not flow logically from the premises. The world abounds with these, and there is a rich treasure trove of fallacious thinking out there. One popular form of the non sequitur is the “genetic fallacy.” It goes something along the lines of: “This argument is false because the person making it is a Republican, or a Democrat, or white, or black, or male, or female, or the member of some other despised group.” Related is the “ad hominem fallacy,” which says, “This argument is false because the person making it is ugly, or stupid, or corrupt, or his mom dresses him strangely.” Arguments where the conclusions do not flow logically from the premises are very common.

A valid argument is one in which, unlike the non sequitur, the conclusion flows logically from the premises. So if I say, “All human beings dance the hokey pokey. Socrates is a human being. Therefore Socrates danced the hokey pokey,” that’s not a non sequitur. Everything in this argument flows validly to the conclusion. However, as you have no doubt noticed, mere validity does not guarantee truth. It is unlikely Socrates danced the hokey pokey. In short, mere validity doesn’t guarantee that the conclusion of an argument is true. You can set up all sorts of arguments that flow logically to a valid conclusion — “All paintings are true. This is a painting of dogs playing poker. Therefore, dogs play poker.” — but the conclusion is false.

That’s why, for an argument to really hold water, it needs to be not only valid, but sound. That is, the premises have to be true, not just logically arranged. It’s no good saying that since all Martians love ice cream, and since you’re eating ice cream, then all Martians love what you’re eating. You must first establish that there is such a thing as a Martian.

Watch out for fallacies

You’d think that with such a fundamentally simple thing as logic, it would be hard to go wrong. But, in fact, fallacies abound. In addition to the fallacies mentioned above, there are many others.

The “straw man fallacy,” for instance, consists of establishing a false premise that looks like, but is not, what is being discussed. It then knocks down that false premise instead of the real one. For example: “When my opponent advocates that parents of small children keep their guns under lock and key, what he means is that Hitler was right to confiscate the guns of the German people and establish an absolute dictatorship. I, for one, oppose Nazi tyranny!” It will be noticed that many fallacious arguments (such as that one) also include a fallacious “appeal to emotion” instead of logic. It will further be noticed that appeals to emotion often are tied to “bandwagon arguments” — “Everybody in this mob I have whipped into a frenzy agrees with me, so I’m right!” — as well as arguments from authority — “Famous and beautiful actress Jenny McCarthy and celebrity TV star Bill Maher both say vaccinations are evil. So they are!”

Some fallacies rely on notions of “false cause,” in which the mere fact that A preceded B somehow proves that A caused B (“The Beatles came to America in February 1964 and in August 1964 LBJ pushed through the Gulf of Tonkin resolution, leading to the debacle of Vietnam. Coincidence? I think not!”). Similarly, “guilt by association” fallacies argue that somebody is wrong or evil because they are somehow connected to people who are wrong or evil (“Jesus cannot be a good man or a prophet. He eats with tax collectors and sinners!”). Relatedly, the “tu quoque” or “no, you!” fallacy argues: “If you are wrong, then I am right,” while the fallacy of “personal incredulity” tries to make oneself the measure of all things: “I don’t see how heavier-than-air flight is possible, so it’s not possible!”

Some fallacies are committed in good faith. Think of them as calculation errors. So lots of people can mistakenly “beg the question” due to having assumptions drilled into them since childhood (“Given that the Bible is the sole source of revelation, can Catholics really show that the Bible is not the sole source of revelation? Certainly not!”).

Others are committed in bad faith, with deliberate cunning and guile in an effort to deceive. For instance, you run into “loaded questions” (“Are you pro-choice or do you want all women everywhere herded into totalitarian theocratic fascist breeder farms and stripped of all human rights?”); “special pleading” (“Well, yes, he did murder his parents, but you have to understand how emotionally damaging it is to be an orphan.”); or “shifting the burden of proof” (“The question is: How do you know I wasn’t rocketed to earth from the planet Krypton?”).

Some fallacies can spring from lazy reliance on “anecdotes,” such as: “How can there be global warming? It snowed at my house yesterday?” Or “cherry-picked evidence” like: “Catholics are murderous tyrants. I mean, Hitler, Himmler, Napoleon: what further evidence do you need?”

Learning to think soundly and weed out fallacies from our thinking is at the very root of judging — not by appearances — but with right judgment.

Mark Shea writes the “Catholic and Enjoying It” blog at www.patheos.com/blogs/markshea/. The next part of his “Thinking with the Mind of Christ” series will appear May 26.